Prefill valve



FIG. 1 is a left view of a prefill valve showing my new design;

FIG. 2 is a right view thereof;

FIG. 3 is a front view thereof;

FIG. 4 is a rear view thereof;

FIG. 5 is a bottom view thereof;

FIG. 6 is a top view thereof; and,

FIG. 7 is a perspective view thereof.

The broken lines shown in the figures are included for the purpose of illustrating portions of the prefill valve and form no part of the claimed design. 

CLAIM The ornamental design for a prefill valve, as shown and described. 